The one you are talking about is Asclepias tuberosa. Tuberosa meaning it grows from a tuberous tap root, and doesn't need as much water after it is established. Are you growing it from seed or purchasing plants? If from seed, it needs cold stratification, so I would put the seeds in the fridge for a month or so, and then sow them in small pots. There are many varieties of what is commonly referred to as butterfly weed, or milkweed. Check out the FAQs here to see various types. It is best to try to grow those that are native to your area - Illinois. You can google "native milkweed Illinois" and this should give you info on milkweed that grows in your area. This is a host plant for the Monarch butterfly. They will only eat milkweed (the caterpillars). There are actually two varieties of A. tuberosa, and as you mention, one is better for clay soil. Prairie Moon nursery usually has both seeds and plants of the type that grows best in clay. Susan Here is a link that might be useful: Prairie Moon

Debra - I was just at a plant farm in Stillwater, OK yesterday. They had pots of tuberosa that had not yet sprouted. If you looked really close at the pots, you could see the tiniest bits of green - but the average eye wouldn't even have noticed. Hang in there - they may come up yet. That being said, I actually lost a tuberosa plant and have no idea why - it had been there three years - was large and beautiful last year - not sure why it didn't come up. The others in my yard are already up and about 6 inches tall. ~Laura

Grows under pine trees? I've been going crazy looking for things that only survive in lots of sun. I'm angling to cut down some pine branches to get some more light to the only "sunny" place on the property where I had to locate the butterfly garden. Do your pines give them filtered sun or part day low light at ground level? We have a stand of White Pines and evergreen trees along the side of the driveway and nothing but weeds and that miserable invasive Chinese Wisteria grow under, around and up them. Milk"weed" qualifies but maybe it won't flower as much without too much light? The foliage is important enough to try them there. The back sides of the pines and evergreens are pretty much bare because of lack of sunlight on the north side but there are places along the south/southeast fronts of these pines to put in milkweed. They survive the root competition from Pine trees? Guess milkweed's long taproots get them the moisture they need. One more question I've been grappling with: I've got mulch all over the Butterfly garden and others to help with moisture and temperature control. Should I not have mulch so things that do will reseed themselves? Under the pine trees there's a perpetually growing layer of pine needles. I'm talking inches deep. Do I have to move mulch/needles to have things find their way to soil contact to have successful natural reseeding or do I need to clear some ground space around plants and the property to allow for natural reseeding? Guess the proper answer is to mulch, collect seeds and sow them around myself. I'm laughing thinking about my father's neighbors and their neat as a pin "lawn and boxwood" yards. People are going to have "weeds" popping up and won't have a clue what they are. Sorry for such elementary questions but all I read since I started this gardening said to mulch and get plenty of sunlight for butterfly attracting plants but I now from reading the forums there are always exceptions and you have to find a way to accomodate the natural surroundings to your purposes.

I always deadhead the milkweeds, especially if the cats have eaten most of the foliage anyway. It stimulates much more foliage for them as well as flowers. (I cut the tops even when they've not had a chance to flower, due to the munching, again to stimulate new leaf growth.) As EricWI says, I really don't need that many seed pods, and my cats often eat the flowers anyway. I try to make sure some seeds make it and get spread around though.